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Is there not some responsibility on the US govt to reasonably protect its infrastructure in a common maritime path? The harbor long preceded the bridge, and whe

Is there not some responsibility on the US govt to reasonably protect its infrastructure in a common maritime path? The harbor long preceded the bridge, and when the bridge was constructed, the harbor had massive container ships moving in and out. No dolphins or starlings around a single point of failure for an entire bridge span? Whole a bridge collapse like this is rare, bridge strikes are not uncommon. It seems like even modest defenses to slow the ship or push some energy aside could have mitigated a collapse.

wombat-man 3y ago
It's a pretty huge ship. How do you stop it?
- willyt 3y ago
  It's pretty shallow[0], looks like about 10m deep around the abutment that was hit; I would think that a big pile of rocks around the abutments that supported the piers on each side of the channel would do it. I just found out you call this RipRap[1] in the US which is cool, in Britain it's called Rock Armour. Total guess but a hundred meters in either direction parallel to the channel by 50 wide? That's about 100,000 tonnes of rock. Something like that? Something close to $50-$200 / tonne delivered? So range of $10m-$40m for both piers, so call it less than $100m. These are guesses which I am making from another continent! so probably the right order of magnitude but not much more accurate than that. I imagine it would have cost a lot less than $8bn dollars, 6 peoples lives and the indirect disruption to the US economy. With hindsight a suspension bridge or a cable stayed bridge with piers well away from the channel might have been more suitable. That style of structure is pretty old-school even for the 1970's, I wonder if it was designed like that because of ground conditions or something, or that was just the cheapest way of doing it in the US at that time and place? [0] https://webapp.navionics.com/?lang=en#boating@15&key=gqjnFz%7CarM https://webapp.navionics.com/?lang=en#boating@15&key=gqjnFz%... [1] https://en.wikipedia.org/wiki/Abutment https://en.wikipedia.org/wiki/Abutment Edit: Changed distribution to disruption.
vr46 3y ago
"I mean, how hard could it be?" It's an incredibly rare event. Retro-fitting things in the water is crazy expensive. Somebody estimated that the force hitting the bridge was 30 Million Pounds. That's a lot of protection needed.
- toomuchtodo 3y ago
  The Florida Sunshine Skyway bridge uses concrete “dolphins” to protect in water support systems, after a similar catastrophic cargo ship collision event. https://maritime-executive.com/article/baltimore-bridge-collapse-revives-hard-learned-safety-lessons https://maritime-executive.com/article/baltimore-bridge-coll... https://www.structuremag.org/?p=20417 https://www.structuremag.org/?p=20417 https://en.wikipedia.org/wiki/Dolphin_(structure) https://en.wikipedia.org/wiki/Dolphin_(structure)
John23832 3y ago
Please tell me what you think the "modest" defense is to divert the mass of a fully loaded container ship? Sometimes bad things happen that cannot be "modestly" prepared for. That is why these vessels are required to be insured.
- ethagknight 3y ago
  Pile of rocks and concrete. Common stuff. It’s a shallow harbor and an interstate bridge. Just needs to reduce impact speed.
alistairSH 3y ago
The bridge opened in March 1977. A cargo ship at that time would have maxed around 3000 TEU (pre-Panamax). Dali is close to 3x that size at just shy of 10,000 TEU. And Dali basically center-punched that bridge support. And swerved very close to the bridge. A dolphin might have mitigated a glancing blow, but I doubt it would have stopped a direct hit such as this. I'm sure the replacement bridge will have more protection, for the optics if nothing else. But, we can't really afford to redesign bridges every time a larger ship is built.
- c0wb0yc0d3r 3y ago
  > A dolphin might have mitigated a glancing blow Are you referring to the animal, or is this slang for some sort of nautical device?
  - woofcat 3y ago
    https://en.wikipedia.org/wiki/Dolphin_(structure) https://en.wikipedia.org/wiki/Dolphin_(structure)
  - alistairSH 3y ago
    The upper span has concrete dolphins, the lower span does not... https://en.wikipedia.org/wiki/Dolphin_(structure)#/media/File:Skyway_Bridge_old_and_new.jpg https://en.wikipedia.org/wiki/Dolphin_(structure)#/media/Fil... What I don't know is how much protection these would offer in a direct hit like the Dali on the Key Bridge. They definitely work for glancing blows and smaller vessels. Would the Dali just push right through/over these? Or would the impact move enough earth (below the surface) to cause the bridge major structural damage?
- ethagknight 3y ago
  But the bridge had _no_ apparent protections even for those 3000 TEU ships. Port of Baltimore spent considerable (federal) funds dredging the harbor to make way for Panamax. A bog standard ring of rocks or concrete or steel piles could have dissipated enough energy to have a very different outcome. I’m just asking, should not the obligation for reasonable protection of the bridge be on the government or port authority?
c0wb0yc0d3r 3y ago
Maps I've seen of the water in the affected area (I'm not sure what the technical term is, nautical chart?) indicate that the channel depth near the bridge is alittle over 15m deep. According to Wikipedia, at its heaviest the dali sits on the shallow side of 15m below the water. I'm not sure what you could reasonably do to impede a ship with such little room.

wombat-man 3y ago

It's a pretty huge ship. How do you stop it?

willyt 3y ago
It's pretty shallow[0], looks like about 10m deep around the abutment that was hit; I would think that a big pile of rocks around the abutments that supported the piers on each side of the channel would do it. I just found out you call this RipRap[1] in the US which is cool, in Britain it's called Rock Armour. Total guess but a hundred meters in either direction parallel to the channel by 50 wide? That's about 100,000 tonnes of rock. Something like that? Something close to $50-$200 / tonne delivered? So range of $10m-$40m for both piers, so call it less than $100m. These are guesses which I am making from another continent! so probably the right order of magnitude but not much more accurate than that. I imagine it would have cost a lot less than $8bn dollars, 6 peoples lives and the indirect disruption to the US economy. With hindsight a suspension bridge or a cable stayed bridge with piers well away from the channel might have been more suitable. That style of structure is pretty old-school even for the 1970's, I wonder if it was designed like that because of ground conditions or something, or that was just the cheapest way of doing it in the US at that time and place? [0] https://webapp.navionics.com/?lang=en#boating@15&key=gqjnFz%7CarM https://webapp.navionics.com/?lang=en#boating@15&key=gqjnFz%... [1] https://en.wikipedia.org/wiki/Abutment https://en.wikipedia.org/wiki/Abutment Edit: Changed distribution to disruption.

vr46 3y ago

"I mean, how hard could it be?" It's an incredibly rare event. Retro-fitting things in the water is crazy expensive. Somebody estimated that the force hitting the bridge was 30 Million Pounds. That's a lot of protection needed.

toomuchtodo 3y ago
The Florida Sunshine Skyway bridge uses concrete “dolphins” to protect in water support systems, after a similar catastrophic cargo ship collision event. https://maritime-executive.com/article/baltimore-bridge-collapse-revives-hard-learned-safety-lessons https://maritime-executive.com/article/baltimore-bridge-coll... https://www.structuremag.org/?p=20417 https://www.structuremag.org/?p=20417 https://en.wikipedia.org/wiki/Dolphin_(structure) https://en.wikipedia.org/wiki/Dolphin_(structure)

John23832 3y ago

Please tell me what you think the "modest" defense is to divert the mass of a fully loaded container ship? Sometimes bad things happen that cannot be "modestly" prepared for. That is why these vessels are required to be insured.

ethagknight 3y ago
Pile of rocks and concrete. Common stuff. It’s a shallow harbor and an interstate bridge. Just needs to reduce impact speed.

alistairSH 3y ago

The bridge opened in March 1977. A cargo ship at that time would have maxed around 3000 TEU (pre-Panamax). Dali is close to 3x that size at just shy of 10,000 TEU. And Dali basically center-punched that bridge support. And swerved very close to the bridge. A dolphin might have mitigated a glancing blow, but I doubt it would have stopped a direct hit such as this. I'm sure the replacement bridge will have more protection, for the optics if nothing else. But, we can't really afford to redesign bridges every time a larger ship is built.

c0wb0yc0d3r 3y ago
> A dolphin might have mitigated a glancing blow Are you referring to the animal, or is this slang for some sort of nautical device?
- woofcat 3y ago
  https://en.wikipedia.org/wiki/Dolphin_(structure) https://en.wikipedia.org/wiki/Dolphin_(structure)
- alistairSH 3y ago
  The upper span has concrete dolphins, the lower span does not... https://en.wikipedia.org/wiki/Dolphin_(structure)#/media/File:Skyway_Bridge_old_and_new.jpg https://en.wikipedia.org/wiki/Dolphin_(structure)#/media/Fil... What I don't know is how much protection these would offer in a direct hit like the Dali on the Key Bridge. They definitely work for glancing blows and smaller vessels. Would the Dali just push right through/over these? Or would the impact move enough earth (below the surface) to cause the bridge major structural damage?
ethagknight 3y ago
But the bridge had _no_ apparent protections even for those 3000 TEU ships. Port of Baltimore spent considerable (federal) funds dredging the harbor to make way for Panamax. A bog standard ring of rocks or concrete or steel piles could have dissipated enough energy to have a very different outcome. I’m just asking, should not the obligation for reasonable protection of the bridge be on the government or port authority?

c0wb0yc0d3r 3y ago

Maps I've seen of the water in the affected area (I'm not sure what the technical term is, nautical chart?) indicate that the channel depth near the bridge is alittle over 15m deep. According to Wikipedia, at its heaviest the dali sits on the shallow side of 15m below the water. I'm not sure what you could reasonably do to impede a ship with such little room.